Electric coil



(I T. ULREY ELECTRIC COIL July 7, 1931.

. Filed May 1. 1928 ll'l! To PUMP INVENTOR C.T. U EY Patented July 7,1931 UNITED STATES PATENT; OFFICE CLAYTON TBIDLE ULREY, OF EAST ORANGE,NEW JERSEY, ASSIGNOR T WESTING- HOUSE LAD COMPANY, A- CORPORATION 01'PENNSYLVANIA.

ELECTRIC COIL Application filed Kay 1, 1828. $erla1 No. 874,181.

This invention relates to electric coils and more particularly to a coilfor heating the metallic arts of electrical discharge devices such as-ray tubes, cathode ray tubes, radio receiving and transmitting tubes,etc. by high frequency induction current. It is not limited to such use,however, but may also be applied to electromagnetic coils.-

It is the usual practice, in such devices, to pretreat the electrodesand metal parts to remove the gases therefrom, which otherwise would bedriven off during the operation of the device. This pretreatment in someinstances can be accomplished bythe heating effect of an operatingcurrent, but onlya few P of the parts can be heated in this way andordinarily it is necessary to resort to heating b means of highfrequency currents induce in the metal arts by a coil disposedexteriorly of the device. In order to be most effective, such highfrequency induction coil should be coupled as closely as possible to thearts to be heated.

eretofore, a helical coil has been generally employed for such heatingand has been positioned about a portion of the envelope by passing thesame over one end of the device. With straight sided envelopes ofregular form, this may be readily accomplished, but

in many types of devices, such as X-ray tubes, the envelope is ofirregular shape with one or more portions of small diameter connected byportions of larger diameter and ordinarily such heating is carried outwhile the device is sealed to an exhaust system. In such cases it isoften impossible to heat certain portions of the device unless a coil isem loyed, of suflicient diameter to pass over t e parts of the envelopeof maximum the objects of the present inven-' about the requlredportions-of the device.

' Other objects and advantages will hereinafter appear.

According to the present invention, I provide an induction coil having aplurality of turns, each consisting of two or more parts, hingedtogether or detachably secured together so that it ma be opened to allowthe coil to be placed a out the envelope of a device undergoingtreatment and to permit the parts of the coil to be reassembled inoperative relation. l V

Reference is had gto the accom anying drawing for a full understanding 0the invention. In the drawings;

Figure 1 is a side elevation of an X-ray or other form of dischargedevice undergoing exhaustion, having my induction coil disposed aboutthe same.

Figure 2 is a perspective view of the coil in an opened position.

Figure 3 is a perspective view of the coil in a closed osition, and

Figure 4 1s an elevation, partly in section, of the coil and supporttherefor.

The vacuum device 1, to be exhausted, is shown in Figure 1, and isconnected by glass tubing 2 to an exhaust manifold 3 connected to avacuum pump not shown). The envelope of the vacuum evice com rises alarge spherical central portion 4 an sections or arms 5 and 6 of smaller"diameter extending therefrom, to the latter of which is connecte thetubing 2 communicating with the exhaust system. The vacuum device isshown as an 8 is shown extending into the central portion of theenvelope-from the op site arm 5.

During the exhausting 0 the device it is necessary to heat the metalparts to incandeyscence to drive out the gases therefrom and to allowsuch liberated gases to be removed from the envelope by the vacuum pump.The filamentary cathode may be heated by passage of current therethroughand the anode may be heated by electron bombardment from the cathode,but the anode and cathode supporting structure cannot be heated in thismanner and it is necessary to resort to high frequency inductionheating. For this purpose I have shown the coil 9 of 1 a high frequencyinduction heating appatwo sections 11 and 12 of arcuate shape.

ratus disposed about the arm 6 in closely cou led relation to theinternal metal parts.

T e high frequency coil, shown in detail in Figures 2, 3 and 4, consistsof a helix 10 of copper or other good conducting material havmg a numberof turns, each consistin fif e sections 11 are supported in parallelspaced relation by insulating members 13 and 14 of bakelite, fiber orother suitable material. The insulating supports may consist of twoabutting strips '15 and 16 recessed as at 17 k and clamped to the endsof the arcuate sections by screws 18 or other suitable fastening means.The sections 12 are similarly supported in spaced relation. The ends ofeach of the sections 12' are provided with tongues 19 a'da ted to bereceived in recesses 20 in the en s of the sections 11 to form aconcesses may be provided with pivot pins 21,

forming a hinge so that the coil may be readily opened and closed andthus be disposed about. the narrow portion of the tube being exhausted.The 0 posite set of tongues and recesses are made to havea snug fit soas to form a ood electrical circuit when the coil is in close position.Terminal portions 22, extending at an angle to the face of the coil, areprovided for each end thereof and ma be secured in sockets 23 and 24carried by an insulating handle 25. The sockets are so constructed thatone or both of the terminals may be swung into the socket upon closin ofthe coil. Conductors28 and 27 supply igh frequency current to the coilfrom any convenient source (not shown). v

Instead of having the coil formed in two sections, as shown, it isobvious that a larger number of sections may be employed and thatvarious means for opening and closing the coil, or temporarily detachinone or more sections, may be provided, an I do not desire to be limitedto the exact details of construction shown and described. By the term'helix I desire to include coils oi both circular and non-circular form,suchas, for instance,-

triangular rectangular or other polygonal form. i

What is claimed is:

1. An electrical coil comprising a plutivity, a plurality of insulatingmembers for I each of'said sets for supporting the sections in spacedparallel relation, the ends of one set ofsections overlapping with thoseof the other section to form a continuous multi-turn helix and beingpivotally connected thereto at one end to permit the sets of sections ofsaid helix to be opened and closed to encircle the object to be heated.

3. A coil for a high frequency induction heating apparatus comprising amulti-turn coil composed of two or more parts pivotally connected alongone side of the coil to divide each turn of the coil into componentparts and to enable the .coil to be opened and closed to enclose anobject to be heated.

In testimony whereof, I have hereunto subscribed my name this 30th dayof A ril 1928.

CLAYTON TRIDLE UIZREY.

